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| Titel |
Long-term total NO2 variations at North Caucasus from 1979 to 2008 |
| VerfasserIn |
Alexander Borovski, Arab Arabov, Nikolay Elansky, Alexander Elokhov, Vladimir Savinykh, Irina Senik, Roman Shumsky, Arseniy Shilkin |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072513
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| Zusammenfassung |
| Nitrogen dioxide observations were carried out at Kislovodsk High Mountain Station (HMS)
of A.M. Obukhov Institute of Atmospheric Physics of Russian Academy of Sciences from
1979 to 2008. The station is located at an unpolluted region of North Caucasus Mountains
(43.7N, 42.7E, 2070 m.a.s.l.). The total and stratospheric NO2 contents were obtained. These
quantities were retrieved from the direct and scattered spectral solar radiation measured for
low solar elevation.
Thirty-years dataset of the total NO2 content is unique by its duration. The characteristics
of diurnal, seasonal and 11-year solar activity cycles, volcano eruptions, QBO and El-Nino
are analyzed. These features are noticeable different from ones detected at some other
NDACC stations.
The average morning and evening total NO2 contents are (4.83±1.31)1015 and
(3.22±0.96)1015 mol/cm2 respectively. Evening data have greater variability. The average
seasonal variations basically are the same as seasonal variability of stratospheric NO2 at
middle-latitudes of the Northern hemisphere. The maximal NO2 content are observed in July,
minimal – in January (4.61015 and 1.91015 mol/cm2 for morning and 6.5 1015 and
3.01015mol/cm2 - for evening).
Minimal seasonal variability of the difference between evening and morning NO2 content
in percentage with respect to daily values for corresponding month takes place in
July-September (36%), maximal – in March (47%).
Decrease of the NO2 content after powerful volcano eruptions is pronounced feature of
these data. The Pinatubo eruption was most powerful (explosivity index K=6). The NO2
content decrease began at the end of 1991. Maximal decrease for the morning values was in
the first half of 1992 (22%).
The increase of total NO2 content from minimum to maximum of 11-year solar cycle is
11% for morning and 7% for evening.
The observations at Kislovodsk HMS were carried out for about 30 years. These unique
data allow to estimate the NO2 trend more correctly. The linear approximation of the NO2
trend from 1979 to 2008 is -7.4±2.4% for 10 years for morning values (-6.6±2.8% for
evening).
Removing of above features from the dataset allows to estimate the QBO and El-Nino
effects on the NO2 content. The analysis confirms the dependence of the total NO2 content on
the QBO and El-Nino. For example, the linear trends for the total NO2, corresponding to the
Eastern and Western QBO phases, are different (13.2±3.8% and 7.5±4.2% for 10 year with
95% confidence interval).
Opportunities of the retrieval of the tropospheric NO2 basing on the simultaneous
observations of the total and stratospheric contents NO2 are analyzed.
The research was partially supported by RFBR grants 10-05-00272, 10-05-01014 and
12-05-31471. |
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